Update makefile and build configuration

Add space to avoid sphinx build error

docs/Makefile

@@ -53,7 +53,7 @@ clean:
 	rm -rf $(BUILDDIR)/*
 	rm -rf config.rst
 
-html: source/config.rst ipynb2rst
+html: source/config.rst
 	$(SPHINXBUILD) -b html $(ALLSPHINXOPTS) $(BUILDDIR)/html
 	@echo
 	@echo "Build finished. The HTML pages are in $(BUILDDIR)/html."
@@ -62,10 +62,6 @@ source/config.rst:
 	python3 autogen_config.py
 	@echo "Created docs for config options"
 
-ipynb2rst:
-	jupyter nbconvert --to rst source/examples/Notebook/*.ipynb --template=source/template --FilesWriter.build_directory=source/examples/Notebook/rstversions
-	@echo "Converted notebooks to rst"
-
 dirhtml:
 	$(SPHINXBUILD) -b dirhtml $(ALLSPHINXOPTS) $(BUILDDIR)/dirhtml
 	@echo

docs/conda_env.yml

@@ -7,6 +7,3 @@ dependencies:
 - nbformat
 - jupyter_client
 - ipykernel
-- pip:
-    - sphinxcontrib_spelling
-    - pyenchant

docs/source/conf.py

@@ -69,7 +69,6 @@ extensions = [
     'sphinx.ext.autosummary',
     'sphinx.ext.mathjax',
     'IPython.sphinxext.ipython_console_highlighting',
-    'sphinxcontrib.spelling',
     'nbsphinx',
 ]
 

docs/source/extending/frontend_extensions.rst

@@ -38,7 +38,7 @@ extension:
     });
 
 .. note::
-    
+
     Although for historical reasons the function is called
     ``load_ipython_extension``, it does apply to the Jupyter notebook in
     general, and will work regardless of the kernel in use.
@@ -112,7 +112,7 @@ place:
     });
 
 .. note::
-    
+
     The standard keybindings might not work correctly on non-US keyboards.
     Unfortunately, this is a limitation of browser implementations and the
     status of keyboard event handling on the web in general. We appreciate your
@@ -184,6 +184,7 @@ actions defined in an extension, it makes sense to use the extension name as
 the prefix. For the action name, the following guidelines should be considered:
 
 .. adapted from notebook/static/notebook/js/actions.js
+
 * First pick a noun and a verb for the action. For example, if the action is
   "restart kernel," the verb is "restart" and the noun is "kernel".
 * Omit terms like "selected" and "active" by default, so "delete-cell", rather